The product is modified from natural starch&period; Under certain temperature and moisture&comma; the chemical bond between molecules is broken and molecule structure changed&period; Starch derivative is achieved through further drying and grinding&period; The product swells and dissolves in cold water and forms paste liquid of certain concentration&comma; which absorbs water&comma; condenses and deposits less&comma; and easily applied&period; It is non-toxic&comma; pollution-free&comma; degradable and environment-friendly&period;